Earliest Flightless Bird Fossil Challenges Darwinian View of Avian Evolution

Chinese scientists have uncovered a 150‑million‑year‑old fossil of Yuezhuornis yangyuanensis, the earliest known flightless bird from the Late Jurassic. The specimen, found in China, demonstrates that not all early birds evolved to fly, contradicting long‑held assumptions—including those of Charles Darwin—that flightlessness arose only after flight had been mastered. The discovery suggests that some avialans may have been flightless from the outset, reshaping our understanding of how flight evolved in the bird lineage. This finding invites a reevaluation of the evolutionary pathways that led to modern birds and highlights the diversity of early avian life.